1. Field of the Invention
The present invention relates to an image processing apparatus, an image processing method, and a program used to reduce color fringing in a color image.
2. Description of the Related Art
A color image pickup system causes a color that cannot be by nature or color fringing around a bright region in an image due to the chromatic aberration of the imaging optical system. Japanese Patent Laid-Open No. (“JP”) 2008-147980 proposes an image processing method for estimating a correction amount of color fringing and for reducing the color fringing by subtracting the correction amount for each color component from an input color image. In addition, JP 2006-014261 reduces color fringing by determining a purple area around white skip pixels as a color fringing area, and by replacing the color fringing pixel with a neighboring pixel of the color fringing region.
However, correction amounts may scatter among neighboring pixels in the image processing method of JP 2008-147980. In particular, when an estimator is configured to estimate a correction amount of color fringing by an image intensity slope between neighboring pixels for each color component, the correction amounts are likely to scatter. By subtracting a scattering correction amount among pixels from the input color image, the color fringing reduced image may contain noises that cannot be contained in the input color image.
On the other hand, the image processing method of JP 2006-014261 replaces the color fringing region with surrounding pixels, and performs shading-off processing configured to reduce scatters caused by the replacements but the color fringing region and the surrounding region are likely to lose sharpness.
Thus, the conventional color fringing reducing processing causes an input colored image to contain noises that cannot exist in the input color image or the color fringing reduced image is likely to lose sharpness.